the fbi classifies them as a domestic terrorist movement. many of these people followed a scary progression from passionate but peaceful, to ultra violent. so when we saw this video on youtube, we wondered were we witnessing the real-time radicalization of a 21-year-old on his way to violence? >> you guys are really overstepping your bounds right now. >> reporter: when we tracked him down, we found a young man who on the surface at least appears average. he lives in his mom's house with his two younger brothers. he rides his bike. but he also straps on a pistol every time he leaves the house, which is perfectly legal here in idaho and openly declares the local police to be his enemy. >> unfortunately, yes. they're the enemy. they're the enemy of anybody who wants to live free. >> produce the information that i require or you will be placed under arrest for obstructing. >> reporter: robert's long series of run-ins with the cops began when he was 18 and got busted for making fireworks. that's when he went online and stumbled into this whole id